Do you know the future direction of rural sewage treatment?
Do you know the future direction of rural sewage treatment?
In February 2018, the General Office of the Central Committee of the Communist Party of China and the General Office of the State Council issued the 'Three-Year Action Plan for the Improvement of the Rural Human Settlement Environment' to step up the treatment of rural domestic sewage and improve the rural living environment. In September 2018, the Ministry of Housing and Urban-Rural Development and the Ministry of Ecology and Environment jointly issued the 'Notice on Accelerating the Formulation of Discharge Standards for Local Rural Domestic Sewage Treatment', requiring all localities to complete the revision of local rural domestic sewage treatment and discharge standards by the end of June 2019. Rural life The formulation of sewage treatment and discharge standards should be based on different location conditions in rural areas, the degree of population concentration in villages, the scale of sewage production, the destination of discharge, and the needs for improvement of human settlements, and in accordance with the principles of zoning and grading, combining leniency and strictness, recycling priority, focusing on actual results, and biased towards management , to determine control indicators and emission limits by category. In April 2019, the Ministry of Ecology and Environment issued the 'Guidelines for the Compilation of Water Pollution Discharge Control Specifications for Rural Domestic Sewage Treatment Facilities (Trial)', pointing out that tail water discharge standards can be appropriately relaxed according to local conditions; encourage the priority selection of nitrogen and phosphorus resources and tail water Take advantage of technology. In the same month, the 'Technical Standards for Rural Domestic Sewage Treatment Engineering' issued by the Ministry of Housing and Urban-Rural Development will be officially implemented in December 2019. The standard systematically reviews the design water quantity and quality, sewage collection system, sewage treatment, supporting facilities, construction and acceptance, and operation. and maintenance are stipulated. Governance goals: By 2020, 130,000 new administrative villages have completed comprehensive environmental improvement, and the domestic sewage treatment rate of the improved villages is ≥ 60%. The development of modern rural society has gone through three processes: (1) early stage: people’s communes, household contracting, migrant workers entering the city; (2) development: land transfer, urbanization; (3) current stage: based on the “Two Mountains Theory” The concept of ecological civilization, the construction of beautiful villages and characteristic towns, and the implementation of the strategy of revitalizing the countryside. Rural domestic sewage has the following characteristics, which make the treatment of rural domestic sewage more difficult. (1) The total amount of pollution sources is astonishing and the distribution is scattered. There are about 700,000 administrative villages in my country, and natural villages are even larger, with a rural population of 800 million. Based on 100 liters of domestic water per capita and a discharge coefficient of 0.8, the cumulative daily domestic sewage is 64 million tons, equivalent to 64 million tons/day, 64 million tons of WWTP, accounting for 30%-32% of the total domestic sewage discharge. (2) Low sewage treatment rate Natural villages are scattered, sanitation problems lead to environmental problems, and pollution sources are quite scattered. After the 'small gathering' and disorderly development of villages, the problems that arise have not been taken into account. At present, the rural sewage treatment rate in my country is only 34%~ 13%) while the urban sewage treatment rate reaches 91.97%, and untreated sewage is discharged randomly, causing serious pollution to the rural environment. (3) Large amount of farming industry in rural areas According to the 'Environmental Statistical Bulletin (2015)', the discharge of chemical oxygen demand from agricultural sources is as high as 10.686 million tons, accounting for 48.06% of the total discharge of chemical oxygen demand in wastewater; The discharge of ammonia nitrogen from agricultural sources is as high as 726,000 tons, accounting for 31.6% of the total discharge of ammonia nitrogen in wastewater. The treatment of rural domestic sewage is an important link in the construction of beautiful countryside, which is related to the happy life of rural people. The comprehensive treatment of rural water pollution is one of the 'main battlefields' of environmental protection in my country for 5-10 years. Current issues (1) Lack of relevant standards, norms and planning guidance, lack of rural sewage discharge standards, and lack of special plans for rural domestic sewage treatment. I believe that with the joint publication of the Ministry of Housing and Urban-Rural Development and the Ministry of Ecology and Environment, they will be resolved one by one. (2) There are many rural sewage treatment technologies, and there is a lack of applicable technical guidelines. The rural population is scattered and the situation varies greatly. In the absence of unified applicable technologies (guidelines or recommendations), local governments cannot choose and distinguish the advantages and disadvantages of technical processes. (3) The amount of treated water does not match the treatment capacity In rural areas, the phenomenon of 'small old villages' and 'hollow villages' is common. At present, the average daily treatment capacity of domestic sewage treatment facilities in rural areas is mostly designed according to the rural household registration population, considering the problem of population flow Insufficient, in the actual operation process, there is a common phenomenon that the operating load is low or even unable to operate due to the small amount of collected water (another reason is that the construction of the collection pipe network is not perfect), which leads to increased construction and maintenance costs and waste of resources. (4) Lack of funds for the construction and operation of sewage facilities Rural domestic sewage treatment facilities are rural infrastructure projects, and their construction, operation, maintenance and supervision require long-term and continuous investment of a large amount of public financial funds, which cannot be afforded by rural areas. Development direction (1) Realize the separation of sewage sources, and carry out technical solutions for resource recovery and treatment. (2) Application of intelligent management and control technology: the number of rural sewage treatment facilities is large and scattered, and the local area lacks professional and technical personnel. Therefore, traditional on-duty operation and maintenance management is unrealistic. Therefore, villages and towns should be built with the help of 'Internet of Things' technology The water cloud platform realizes intelligent maintenance and management, that is, through online instruments, it realizes remote online monitoring, unattended and on-site, remote control combined with intelligent management and control. Through the intelligent management and control platform technology, the operation status of the plant can be controlled in real time, the optimal scheduling of people, vehicles, and objects can be realized, the daily personnel investment can be reduced, and the management efficiency and level can be improved, thereby improving the operation efficiency of treatment facilities and helping rural sewage treatment from management. This article is compiled based on the speeches made at the '2019 South China Rural Sewage Treatment Technology Seminar' forum at the same time as the Expo. If there is any inappropriateness, please correct me.